Disk for water meters



Sept. 8, 1925.

J. THOMSON DISK FOR WATER METERS Original Filed March 3. 1925 INVENTOR;

Patented Sept. 8, 1925,

UNITED STATES PATENT OFFICE...

JOHN THOMSON, OF BROOKLYN, NEW YORK.

msx FOR-WATER METERS.

Application filed larch 8, 1928, Serial No. 622,700. Renewed-February12, 1925.

To all whom it may concern:

Be it known that I, JOHN THOMSON, a citizen of the United States, and aresident of the borough of Brooklyn, city and State of New York, haveinvented Improvements in Disks for Water Meters, of which the followingis a specification.

This invention relates to disk water meters, consisting of animprovement in the disk itself; and its objects are to decrease thefrictional resistance and increase the endurance thereof. As hereinemployed, the unitary term disk includes its ball, being the adoptednomenclature of common parlance.

It is deemed within the truth to state that nine-tenths of the disks inwater meters, of which many millions are now in use, are formed ofhard-rubber, machined from rough stock. Their coeficient of friction isrelatively low in that, when acting against bronze or brass, watersomewhat serves as a lubricant. v

It goes without saying that even a nominal diminution of the presentfrictional coefiicient of disks, or the disk-action, would both increasethe registration of meters at the sensibility rates of flow and enhancetheir endurance when run rapidly and for long periods of time. To thatend, disks so have been made in which some minor portion of the compoundis pulverized graphite, thoroughly pre-mixed in the mass. Thus, it willbe apparent that but a nominal part of the graphitic content will be inevidence at as the superficial surfaces of the disk, which is the objectof introducing it; moreover, the unctuous characteristic of graphite isdetrimental to its binding efficiency and sacrifice of tensile strengthensues.

In the present instance a thin film plating or sheathing of puregraphite, preferably in the form of a defloculated dust, is primarilyapplied to the surfaces of the rubber in such manner and with sucheffect that the graphite is as completely imprisoned and pressure-weldedto thev surfaces as if it had been mixed with and permeated thecompound.

The accompanying drawings, whichform a part of this specification, areintroduced to assist in visualizing a preferred process or maneuver forrealizing the benefits of this invention.

' Figure 1 is a plan view of a water meter disk in which the usualdiaphragm slot is in 65 dicated in dotted lines;

Figure 2 comprises a half edge elevation and a half transverse sectionof the disk at the state when the graphitic dust is first appliedthereto, that is in ,a pigmental free state; and

Figure 3 also comprises a half edge elevation and a half transversesection of thesame disk, as in Figure 2; but at that state ofthemaneuver when the graphitic dust has been permanently pressure-weldedupon and embedded in its surfaces.

The preferred grade of graphite for the purpose here-of is that known bythe tradename of Aquadag, produced by the electrlc furnace process ofAcheson, whose state of comminution is unique in the art, bordering uponthe domain of the molecular. It is wholly devoid of earthly'grit and, ina practical sense, is pure. When waterpreferably distilled-is mixed withthis dust it can be brushed, smeared or sprayed upon surfaces as in theinstance of paint or paste. Now, when a surface of any material ismade-very clean, as by means of alcohol; is coated with thishydro-graphitic dope; held until the free water evaporates and is thensomewhat rubbed with a soft cloth its intimacy of adherance to thesurface simulates that of glue or varnish. This is really an astonishingresult; for, as there is no binder other than water and even it has beenevacuated, the justifiable assumption is that the graphite wouldreappear as dust; but it does not. Perhaps it might be termed an 0articulated 'film. The reasons for this phenomenon are more or lesshypothetical and need not be here discussed.

In certain cases, as when the highest state of purity in the appliedgraphite is not essential, a minor quantity of sodium silicate may beadvantageously added to the dope.

The thickness of the pigmental graphitic films which can thus be readilyapplied to surfaces range from a few ten-thousands of an inch upwardly.

In the realization hereof, the first step in the maneuver is to providea pre-formed, hard rubber disk A, Figure 2, having a sprue as b, coatingthe surfaces with a film 1 of graphite as c, 0 C according to theprocedure just set forth. The dimensions of the disk are to be such thatit can be freely entered and clamped within'a molding-die,

' here indicated by the dotted'outline B, the

"plastic, that is a condition which may be characterized as past-y,somewhat like heated wax, and flowable, under pressure, as inthe case offluids.

The third step is to apply pressure upon the conical head, d, of thesprue, causing it to move downwardly, displace the underlying mainvolume of rubber and compelling it to flow radially, whereby tocompletely fill the die-cavity.

The fourth step is topermit the disk to cool in place, the formingpressure being meantime maintained.

Thus, the removed disk, Figure 3, wil

have acquired the exact volume and dimensions of the die-cavity and be,in fact, a finished product except as to the removal of the tit e, whichrepresents the. material in excess of that required to-compensate forthek lesser dimensions of the pie-formed dis The present relevancy ofthe aforesaid steps is to publicly disclose adequate ways and means forrealizing the paramount feature of this invention. Thus, undertheconditions herein shown and described, the pressure which is readilyimpartable to the plastic but highly viscuous rubber is limited only bythe resisting capacity of the mold. As the rubber is rolled radiallyoutward the applied and persistently adherent film of graphite iscorrespondingly compressed, driven into the superficial surfaces of thedisk, and burnished to whatever degree of smoothness may have beenimparted to the contacting surfaces of the die. I It is no figure ofspeech to state that the superficial surfaces of the disk areconsiderably impregnated with graphitic dust, the two substances beingpressure-welded together. 'For example, it is as if minute metallicglobules, such as zinc-dust, were driven into theplastic rubber which,when solidified, would intimately hold the globules, like gravel inconcrete.

Numerous needle-like points and hairlines of rubber may break throughthe graphite film, but that is a desirable feature; for graphite isthereby imprisoned between vertical walls of rubber and securely heldagainst future dislodgement. Hence, the

graphitic film may not be continuous and unbroken;'but, as when viewedmicroscopically, its appearance may simulate that of a crazy-crackedweb. Be all this as it may, the material result is afdisk of suchsmoothness, and subtending such a low co-efficient of friction as couldonly be otherwise attained by forming the disk who-11y from when raw orpro-vulcanized rubber directly impinges upon the die-surfaces; which, by

avoidance of deformation and saving in time, are in themselvescontingent advan tages of distinct importance.

By thus diminishing the oo-efiicient of friction, the sensibility ofdisk water meters is substantially enhanced and their ultimate enduranceis correspondingly increased, yet

the cost of realizing these betterments is merely nominal.

It is not deemed necessary to amplify, as by specific enumeration, thatthis system of graphitically coating hard-rubber, or analogouscompounds, is applicable to various articles and uses where diminutionof friction is desirable.

What I claim is:

1. A hard-rubber water meter disk having a superficial coating ofgraphitic dust impressed thereon andtherein when the said disk is in aplastic condition.

'2. A hard-rubber water meter-disk having a superficial coating ofhighly comminuted graphite primarily applied as a free pig ment andthenafter impressed u on and within the disk-surfaces when t ehardrubber is in a plastic condition.

3. In disk-action water meters, a hardrubber disk Whose bearing surfacesare coated or plated with films of comminuted graphite, the particlescomprising said films being impressed upon and into the superficialsurfaces of the hard-rubber when the latter is in a state of plasticity.

4. In disk-action water meters, a hardrubber disk whose bearing surfacesare plated and impregnated with films of comminuted graphite, theparticles comp-rising said films being pressure-welded upon and intosuperficial surfaces of the hard-rubber when the latter has'been heatedto a condition characterizable as plastic.

This specification signed on the 28th day of February, A. 1)., 1923.

JOHN THOMSON.

